A week after graduating from her school, Brewer arrived in Melbourne to look for acting work.[3][5] While she was in the city, Brewer successfully auditioned for the ongoing role of Kate Ramsay in the long-running soap opera Neighbours.[3] The actress relocated to Melbourne for filming and she made her debut as Kate on 15 May 2009.[3][5] The following year, Brewer was nominated for the Most Popular New Female TalentLogie Award.[6] In July 2013, Brewer celebrated filming 1000 episodes.[7]

After five years of playing Kate, Brewer confirmed her departure from Neighbours in November 2013. Brewer decided to quit the show to pursue new acting projects.[8] She filmed her final scenes the following month.[9] Brewer's character was killed off and she admitted that she was delighted with Kate's exit storyline.[10]

On 22 May 2014, it was announced that Brewer had been cast in the newly created role of Ivy Forrester in the American soap opera The Bold and the Beautiful. Brewer's character is the niece of established character Eric Forrester (John McCook).[11] Brewer began filming on 24 May.[12] She had a three-year contract with the show and made her debut as Ivy in July 2014.[11][12] Brewer appeared in a documentary special celebrating Neighbours' 30th anniversary titled Neighbours 30th: The Stars Reunite, which aired in Australia and the UK in March 2015.[13][14] In January 2018, Brewer announced her decision to quit The Bold and the Beautiful; explaining her decision, Brewer cited Margot Robbie as her inspiration, in her own desires to achieve other acting opportunities.[15]